U.S. patent application number 11/150319 was filed with the patent office on 2006-06-08 for oil pan of internal combustion engine.
Invention is credited to Masatoshi Hada, Yasuki Ohta.
Application Number | 20060118077 11/150319 |
Document ID | / |
Family ID | 34980013 |
Filed Date | 2006-06-08 |
United States Patent
Application |
20060118077 |
Kind Code |
A1 |
Hada; Masatoshi ; et
al. |
June 8, 2006 |
Oil pan of internal combustion engine
Abstract
The oil pan includes an oil introducing means that has an oil
introducing plate. The oil introducing plate has an insertion hole
for receiving a sucking portion of an oil strainer. The oil
introducing plate extends from the periphery of the insertion hole
toward a side wall of the oil pan. The oil returned from the first
oil return passage is introduced to flow along the oil introducing
plate via an oil falling hole formed in a baffle plate that is
positioned at the bottom of a crank case of the internal combustion
engine. The oil introducing means further includes a plurality of
inclined wall portions mounted on a bottom portion of the oil pan
in the vicinity of the side wall of the oil pan in order to support
the oil introducing plate. Opening portions are formed between the
inclined wall portions and the bottom portion of the oil pan. The
oil introducing plate of the oil introducing means is located just
below the oil falling hole formed in said baffle plate.
Inventors: |
Hada; Masatoshi;
(Nagoya-shi, JP) ; Ohta; Yasuki; (Nagoya-shi,
JP) |
Correspondence
Address: |
DENNISON, SCHULTZ, DOUGHERTY & MACDONALD
1727 KING STREET
SUITE 105
ALEXANDRIA
VA
22314
US
|
Family ID: |
34980013 |
Appl. No.: |
11/150319 |
Filed: |
June 13, 2005 |
Current U.S.
Class: |
123/196R |
Current CPC
Class: |
F01M 2011/023 20130101;
F01M 11/02 20130101; F01M 11/0004 20130101; F01M 2011/0033
20130101 |
Class at
Publication: |
123/196.00R |
International
Class: |
F01M 11/00 20060101
F01M011/00 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 7, 2004 |
JP |
2004-205316 |
Claims
1-4. (canceled)
5. An oil pan mounted on a bottom part of a crank case of an
internal combustion engine, the internal combustion engine
including a first oil return passage extending from a cylinder head
to an oil pan through a crank case and a baffle plate disposed at a
bottom of the crank case, and a second oil return passage extending
directly from the cylinder head to the oil pan, wherein: the oil
pan collects oil returned from said first oil return passage and
oil returned from said second oil return passage; the oil pan
comprises an oil introducing means; said oil introducing means
comprises: an oil introducing plate having an insertion hole for
receiving a sucking portion of an oil strainer, the oil introducing
plate extending from the periphery of said insertion hole toward a
side wall of the oil pan, wherein the oil returned from said first
oil return passage is introduced to flow along said oil introducing
plate via an oil falling hole formed in said baffle plate: a
plurality of inclined wall portions mounted on a bottom portion of
the oil pan in the vicinity of the side wall of the oil pan in
order to support said oil introducing plate; and opening portions
formed between the inclined wall portions and said bottom portion
of the oil pan, wherein the oil introducing plate of the oil
introducing means is located just below said oil falling hole
formed in said baffle plate.
6. The oil pan according to claim 5, wherein said oil introducing
means further includes sheet-like extensions extending from said
inclined wall portions at respective top ends of said opening
portions.
7. The oil pan according to claim 5, wherein said second oil return
passage is open at a bottom end that is submerged in the oil
collected within the oil pan; and a part of each of said opening
portions is open toward the bottom end of said second oil return
passage.
8. The oil pan according to claim 6, wherein said second oil return
passage is open at a bottom end that is submerged in the oil
collected within the oil pan; and a part of each of said opening
portions is open toward the bottom end of said second oil return
passage.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to an oil pan of internal
combustion engine.
[0003] 2. Description of the Related Art
[0004] Oil for lubricating respective sliding portions of an
internal combustion engine is deposited in the oil pan of the
internal combustion engine and supplied to those respective sliding
portions of the internal combustion engine by means of an oil pump
and the like through an oil strainer.
[0005] After lubricating a sliding surface between a cylinder and a
piston and bearings of a connecting rod and crank shaft of the
sliding portions of the internal combustion engine, oil floats in
the condition of mist within a crank case. The oil is heated by a
high-temperature blow-by gas leaking from the sliding surface
between the cylinder and the piston, drops onto a baffle plate, and
thereafter returns to the oil pan.
[0006] As regards the internal combustion engine, for example,
Japanese Utility Model Application Laid-Open NO. HEI4-71716
discloses a structure for preventing the oil strainer from being
exposed over oil surface and sucking air due to tilt of the oil
surface generated at the time of acceleration or deceleration for
startup or stop of a vehicle or turning. Therefore, the oil is
stably supplied to the respective sliding portions of the internal
combustion engine, thereby improving wear resistance.
[0007] According to the structure disclosed in this document, a
lidded cylindrical baffle plate for defining an oil holding space
to surround the oil strainer is provided on an oil sump within the
oil pan. This lidded cylindrical baffle plate has a communicating
opening hole which communicates with the interior of the oil pan.
The oil strainer is inserted into the communicating opening at its
lid portion. A dent portion which communicates with the interior of
the oil pan is formed at the bottom of this cylindrical body.
Consequently, by holding sufficient amount of oil within the oil
holding space by this cylindrical body, oil can be supplied to the
respective sliding portions of the internal combustion engine
stably even when oil surface is tilted.
[0008] However, the structure of such oil pan allows hot oil
recovered after floating within the crank case to enter into the
oil holding space through the communicating opening hole formed in
the lid portion on the top of the baffle plate. Consequently, the
hot oil is supplied to the respective sliding portions of the
internal combustion engine from the oil strainer, thereby possibly
badly affecting the lubrication performance.
SUMMARY OF THE INVENTION
[0009] The oil pan of the internal combustion engine of the present
invention intends to prevent a drop in the viscosity of oil and
deterioration of the oil to improve the lubrication performance
thereof by cooling the oil within the oil pan to equalize the
temperature of the oil.
[0010] According to a first aspect of the present invention, an oil
pan collects oil returned from a first oil return passage and oil
returned from a second oil return passage of an internal combustion
engine. The first oil return passage extends from a cylinder head
to an oil pan through a crank case and a baffle plate disposed at a
bottom of the crank case. The second oil return passage extends
directly from the cylinder head to the oil pan.
[0011] The oil pan includes an oil introducing means that has an
oil introducing plate. The oil introducing plate has an insertion
hole for receiving a sucking portion of an oil strainer. The oil
introducing plate extends from the periphery of the insertion hole
toward a side wall of the oil pan. The oil returned from the first
oil return passage is introduced to flow along the oil introducing
plate via an oil falling hole formed in a baffle plate that is
positioned at the bottom of a crank case of the internal combustion
engine. The oil introducing means further includes a plurality of
inclined wall portions mounted on a bottom portion of the oil pan
in the vicinity of the side wall of the oil pan in order to support
the oil introducing plate. Opening portions are formed between the
inclined wall portions and the bottom portion of the oil pan. The
oil introducing plate of the oil introducing means is located just
below the oil falling hole formed in said baffle plate.
[0012] As a consequence, hot oil flowing down from the first oil
return passage is introduced to the side wall of the oil pan along
the oil introducing plate of the oil introducing means. The oil can
be cooled excellently by the side wall of the oil pan which keeps
in contact with the atmosphere. Further, by introducing oil toward
the side wall, entire oil within the oil pan is circulated, thereby
eliminating oil retaining zone in the oil pan. Further, the
temperature of the oil in the oil pan is equalized excellently and
that oil is introduced to the sucking portion of the oil strainer
through the opening portions in the inclined wall portions of the
oil introducing means. Therefore, the oil can be supplied to
respective portions of the internal combustion engine excellently.
As a result, drop in the viscosity of oil and deterioration of the
oil can be prevented.
[0013] The oil introducing means is provided on the bottom of the
oil pan. The oil introducing plate contains the insertion hole
through which the sucking portion of the oil strainer is inserted.
Therefore, the oil introducing means can be fixed on the bottom of
the oil pan excellently and further, the oil strainer can be
installed on the oil introducing means compactly.
[0014] According to a second aspect of the present invention, the
oil introducing means further includes sheet-like extensions
extending from the inclined wall portions at respective top ends of
the opening portions.
[0015] Therefore, hot oil flowing down from the first oil return
passage runs over a long distance along the sheet-like extensions
before introduced to the side wall of the oil pan excellently. As a
consequence, fluidity of oil in the oil pan is improved thereby
eliminating the oil retaining zone. Further, by feeding oil along
the side wall of the oil pan, active radiation of heat to the
atmosphere is enabled.
[0016] According to a third aspect of the present invention, the
second oil return passage is open at a bottom end that is submerged
in the oil collected within the oil pan. A part of each of said
opening portions is open toward the bottom end of the second oil
return passage.
[0017] Hot oil flowing down from the first oil return passage runs
to the side wall of the oil pan along the oil introducing plate of
the oil introducing means. The oil is cooled by the side wall and
is then introduced to the sucking portion of the oil strainer
through the opening portion in the oil introducing means. At this
time, cooled oil introduced from the cylinder head flows down from
the bottom end of the second oil return passage into the oil pan
and then flows toward the opening portion of the oil introducing
means. As a consequence, hot oil and cooled oil flowing down from
the second oil return passage are mixed excellently so as to
equalize. Therefore, the temperature of entire oil in the oil pan
is lowered. Further, due to the mixing of the hot oil and the
cooled oil, a positive tide is generated in entire oil within the
oil pan, so that oil retaining zone in the oil pan diminishes and
consequently, the temperature of the oil can be equalized further
excellently.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] FIG. 1 is a schematic longitudinal sectional view of the
internal combustion engine;
[0019] FIG. 2 is an enlarged perspective view of major portions in
case where an oil introducing means is provided within an oil pan
of the internal combustion engine; and
[0020] FIG. 3 is an enlarged perspective view of major portions
showing a modification of the oil introducing means.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0021] Hereinafter, a preferred embodiment of the present invention
will be described with reference to the accompanying drawings.
[0022] FIG. 1 is a longitudinal sectional view of an internal
combustion engine. In the internal combustion engine 1, a cylinder
head 3 is provided on the top of a cylinder block 2. A crank case 4
is connected to the bottom of the cylinder block 2. An oil pan 5
for collecting oil is provided below the crank case 4.
[0023] A head cover 3a is mounted on the top of the cylinder head 3
to cover valve driving parts including cam shafts 7a, cams 7b and
valve springs 8 provided within the cylinder head 3. The cylinder
head 3 and the head cover 3a define a cam chamber 6.
[0024] A piston 9 and a connecting rod 10 are provided within the
cylinder block 2. A crank shaft 11 and a counterweight 12 are
provided within the crank case 4. As the internal combustion engine
operates, the counterweight 12 rotates in the direction indicated
with an arrow.
[0025] A curved baffle plate 13 extends along a rotary trajectory
of the counterweight 12 of the crank shaft 11 on the bottom of the
crank case 4. Oil lubricates the sliding surface between the
cylinder and piston. Also, oil lubricates the valve driving parts
including the cam shaft 7a, the cam 7b and the valve spring 8
located on one side of the cylinder head 3. These lubricated oils
drop into the crank case, thereby lubricating the connecting rod
10, the crank shaft 11 and the like. Thereafter, the oils return
into the oil pan 5 located below through oil falling holes 13a,
13a, 13b formed in the baffle plate 13. In this way, a first oil
return passage 15A is defined.
[0026] Further, a water jacket 14, in which cooling water for
cooling the cylinder flows, is provided sideway of the piston 9
within the cylinder block 2. A second oil return passage 15B is
formed vertically on the outer periphery side of that water jacket
14.
[0027] This second oil return passage 15B is defined in the
cylinder head 3, the cylinder block 2 and the crank case 4. Oil
returns to the oil pan 5 via the second oil return passage 15b
after lubricating the valve driving parts including the cam shaft
7a, the cam 7b and the valve spring 8 located on the other side of
the cylinder head 3. The second oil return passage 15b is formed in
the vertical direction of the internal combustion engine. A bottom
end opening portion 15C of the second oil return passage 15B is
located at a position submerged in the oil collected within the oil
pan 5.
[0028] The oil that returns to the oil pan 5 through the second oil
return passage 15B is cooled by cooling water flowing through the
water jacket 14 in the halfway of the returning path. Therefore,
the temperature of the oil is lowered before returning into the oil
pan 5.
[0029] On the other hand, within the crank case 4 defining the
first oil return passage 15A, the connecting rod 10 and the crank
shaft 11 are lubricated by the oil that has lubricated the sliding
surface between the cylinder and the piston 9 and by the oil that
has lubricated the valve driving parts including the cam shaft 7a,
the cam 7b and the valve spring 8 located on the one side of the
cylinder head 3. At the same time, the oils are splashed by the
connecting rod 10, the counterweight 12 and the like, which rotate
at high speeds when the internal combustion engine is operated.
Therefore, the oil turns into mist whose surface area per unit
volume is large, thereby increasing the quantity of heat received
from hot blow-by gas leaking from the sliding surface between the
cylinder and the piston 9. As a consequence, the temperature of the
mist gas is kept high. This hot oil is returned to the oil pan 5
through the oil falling holes 13a, 13b in the baffle plate 13 as
described previously.
[0030] According to this embodiment, as shown in the enlarged
perspective view of major portions of FIG. 2, an oil introducing
means 16 is provided within the oil pan 5.
[0031] The oil introducing means 16 is fixed on a bottom wall 5b of
the oil pan 5 and includes an oil introducing plate 16a, inclined
wall portions 16b and fixing pieces 16c to be fixed on the bottom
wall 5b of the oil pan 5. The center of the oil introducing plate
16a has an insertion hole 16d in which an oil strainer 18 is to be
installed.
[0032] A sucking portion 18a is located at a bottom end of an oil
strainer 18 and is inserted through the insertion hole 16d in the
center of the oil introducing plate 16. The sucking portion 18a is
disposed in the vicinity of the bottom wall 5b of the oil pan S
located below. An oil passage for feeding oil to an oil pump (not
shown) is provided in the top face of the oil strainer 18.
[0033] Therefore, the oil introducing means 16 surrounds the
sucking portion 18a of the oil strainer 18. The oil introducing
plate 16a of this oil introducing means 16 extends from the
periphery of the insertion hole 16d toward the side wall of the oil
pan so as to be positioned just below the oil falling hole 13b
located at the lowest position of the baffle plate 13.
[0034] That is, hot oil flows down on this oil introducing plate
16a through the oil falling holes 13a, 13a, 13b in the baffle plate
13 and then smoothly flows along the oil introducing plate 16
toward the outer peripheral side or toward the side wall 5a of the
oil pan 5.
[0035] Further, drain side opening portions 17a are formed in the
inclined wall portion 16b of the oil introducing means 16 and are
directed to the bottom end opening 15C of the second oil return
passage 15B. Preferably, the drain side opening portions 17a are
formed in the vicinity of the bottom end opening 15C of the second
oil return passage 15B.
[0036] In the inclined wall portion 16b, a rear side opening
portion 17b is formed on an opposite side to the drain side opening
portion 17a.
[0037] Thus, cooled oil flows out from the bottom end opening 15C
through the second oil return passage 15B and can flow into the oil
introducing means 16 through the drain side opening portions
17a.
[0038] Hot oil dropping on the oil introducing plate 16a of the oil
introducing means 16 flows to the side wall 5a of the oil pan 5
along the oil introducing plate 16a. Because the side wall 5a of
this oil pan 5 keeps contact with the atmosphere, while hot oil
flows to the bottom wall 5b along the side wall 5a, heat is
radiated excellently to the atmosphere so that the temperature of
oil is reduced. With the temperature dropping gradually, the oil
flows into the oil introducing means 16 through the drain side
opening portion 17a and the rear side opening portion 17b.
[0039] At this time, cooled oil flowing down from the second oil
return passage 15B is mixed with hot oil excellently so that the
entire temperature of oil within the oil pan 5 is equalized.
Further, positive tides is generated in oil within the oil pan 5
due to the mixing of high temperature and low temperature oils,
thereby eliminating oil retaining zone within the oil pan 5.
Consequently, with the temperature of entire oil in the oil pan 5
dropped, the oil can be supplied to respective portions of the
internal combustion engine 1 from the sucking portion 18a of the
oil strainer 18. As a result, drop in the viscosity of oil can be
prevented and deterioration of oil can be blocked, so that
excellent lubrication performance with oil is secured.
[0040] FIG. 3 shows a modification of the oil introducing means 16.
The oil introducing means 16 of FIG. 3, has sheet-like jaw portions
16e formed above the opening portions 17a and 17b so that they
project toward the side wall 5a of the oil pan 5.
[0041] By providing these jaw portions 16e on the top end of the
respective opening portions 17a and 17b, hot oil can flow along the
oil introducing plate 16a over a longer distance so as to be
introduced to the side wall 5a of the oil pan 5. Further, the flow
speed of oil flowing toward the side wall 5a of the oil pan 5 can
be accelerated. While the oil flows from the side wall 5a to the
bottom wall 5b, heat is radiated to the atmosphere so that the oil
is cooled excellently. Further, the oil retaining zone within the
oil pan 5 can be eliminated excellently.
* * * * *